The world was a much different place back then: China had just overtaken the U.S. as the world's largest economy by one measure, threats from ISIS were on the rise, and bitcoin — already highly volatile back then — tumbled by 58 percent.

CNBC looks at what happened globally around the time oil prices were at current levels in 2014:

China's economy vaults to first place in one important metric

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President of the People's Republic of China Xi Jinping.

In October 2014, the Chinese economy topped the American one in terms of purchasing power parity, according to IMF data. By that measure, the size of the Chinese economy estimated at around $17.6 trillion at the time — just slightly ahead of the U.S.' $17.4 trillion.

Three years later, China's economy jumped to $25.1 trillion by the PPP measure, while the U.S.'s grew to $20.2 trillion, according to the IMF's World Economic Outlook report in October 2017.

What was Trump up to?

Donald Trump spent 2014 contemplating the possibility of running for the White House. At the same time, he was busy posting on Twitter on topics ranging from calling for the impeachment of then-President Barack Obama to motivational quotes. Here are some of his tweets:

The box office

Brent crude futures last traded at roughly Monday's levels on Dec. 2, 2014, while the WTI crude futures last reached current levels on Dec. 5, 2014.

In the weekend that followed, Dec. 6 and 7, the movie "The Hunger Games: Mockingjay Part 1" topped the global box office by taking in $22 million worldwide, according to an online database run by IMDb. "Penguins of Madagascar" was a distant second at $10.9 million of gross earnings that weekend.

Neither film was nominated for an Academy Award.

Hong Kong's 'Umbrella Revolution'

The 2014 protest, dubbed the "Umbrella Revolution" as student activists used umbrellas to protect themselves from police pepper stray, erupted over mounting frustrations about Beijing's meddling in Hong Kong politics. Protesters were unhappy that China would pre-approve candidates for the elections of a new chief executive — the head of government in Hong Kong — in 2017.

The movement started on Sept. 28, 2014 and, at its peak, rallies drew more than 100,000 attendees and protesters occupied central areas such as Mong Kok and Admiralty — bringing traffic into those sites to a halt.

Umbrellas are opened as tens of thousands come to the main protest site one month after the Hong Kong police used tear gas to disperse protesters October 28, 2014 in Hong Kong, Hong Kong.

Rise of the Islamic State

By December 2014, the jihadist group controlled large swathes of territory in Syria and Iraq. In June of that year it had adopted the name "Islamic State" to reflect its ambitions to expand beyond the two countries. The group would later add parts of Nigeria, Pakistan and Egypt to its territory.

The year 2014 also saw the U.S. launching its first airstrikes against the group. The U.S. and its Arab allies bombed Syria in September that year, killing at least 70 Islamic State fighters during the first strikes.

Bitcoin was just above $300

Bitcoin came into the limelight at the end of 2013 when its price rose above $1,000. But 2014 was a rough period for the cryptocurrency: It plunged 58 percent during that time to close the year at $319.70, according to Coindesk's Bitcoin Price Index, which tracks prices from major digital currency exchanges.

Notable developments around that time in the cryptocurrency space included Microsoft's acceptance of bitcoin as a form of payment, joining the likes of PayPal, Dell and Expedia.

Volatility in the price of bitcoin slowed down the public's acceptance of cryptocurrencies. But bitcoin would later stage a comeback to trade above $19,000 — its all-time high thus far — in December 2017.

A win for same-sex couples

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Scotland's new law on same-sex marriages came into effect in December 2014. The legislation allowed civil partnerships to be converted to marriages, and was used for the first time by Douglas Pretsell from Edinburgh and his Australian partner Peter Gloster, the BBC reported.

The law came about after a 2014 survey revealed that 68 percent of Scots agreed that same-sex couples should have the right to marry, compared to 41 percent who thought the same in 2002.